As the title says,
I would like to know all the possiblities for a blow by???
I have a new build engine !! it is Street Ported and pined!! the first three week it wasn't smoking but about month or 6 weeks later, it starts to smoke a little.

Whats even more wierd. I have a GT40 .88 A/R that made 284@16psi.. Not Normal AFR is 10.3-11 no matter how more boost i increase still richer it get !!!!!

also blow by.. what can causes it?????????????
any inputs from the pros.

 

i'm no pro, but i think the ports being ported too large will cause blow-by, especailly with a big turbo.

 

how could that possibly be?? and how can i fix it ? if so?

 

3 possibilities. If the ports were cut too far in, the oil control rings may not be sealing. The builder may not have replaced the oil control rings and/or the oil control o-rings. The turbo oil seal may be leaking.

When does it smoke the most? On start up, then goes away, when under heavy boost or on hard decell? Each one can indicate a different source for the leak.

 

it doesn't smoke when its cold. it start smoking when I hard accelerate then it smokes a little.. but when i hard boost it and let go of the gas, it smoke like crazy for 5-10 min. and when i shutt down the car and start it again. it also smoke like crazy.

 

Talk to the builder and ask if the oil control rings and the oil control o-rings were replaced. Another possibility is too much oil pressure going to the turbo. The feed line usually has a jet in the feed line to reduce oil pressure, especially if you're running a high pressure oil pressure regulator.

 

Check your oil return line from the turbo to the engine. Make sure its not crimped.

 

Thanks guys you all have the best inputs.
I'll try to check on all of the addressed possibilities.

I just hope nothing serious !!

thanks again.

 

whats a little oil smoke at startup mean?

 

Nothing. It's fairly normal.

 

Ditto on the oil return. Had a dsm that would smoke and it ended up being the return had a gasket that was partially blocking the flow

 

TROCHOID, when you were talking about leaking turbo oil rings, what is involved in replacing those?

 

Turbo is oil feed and cooled, when they start leaking, they get rebuilt.

 

My understanding is that too much back pressure up the turbo oil return line will bust the seal in the turbo, thus why you always must have the oil return gravity fed.